1. Field of the Invention
The present invention relates to an image processing method and apparatus and, more particularly, to an image processing method and apparatus in which an image or an image recorded in an analog recording medium such as a microfilm, paper or the like is read and then processed digitally so as to be recorded in another recording medium of digital type such as an optical disk or a magnetic tape.
2. Description of the Related Art
In general, office automation facilities, particularly for filing, are required to meet the following demands:
(1) High-speed input of a lot of information PA0 (2) High-speed reproduction PA0 (3) Validity as means of legal documentation PA0 (4) Long-term storage capability PA0 (5) Standardization of recording medium PA0 (6) High resolution PA0 (7) High recording density PA0 (8) High retrieval speed PA0 (9) Linkage with communication network PA0 (10) Capability of providing instantaneous availability PA0 (11) Ease of updating of data
(For example, capability for enabling reading of data immediately after writing, without necessitating development or fixing)
In general, microfilms have been recognized as filing means which cope with demands (1) to (7) above, whereas optical disk files are superior in that they meet the demands (7) to (11) above. Proposal has been made, therefore, for a composite filing system in which a microfilm filing system and an optical disk filing system are combined with each other. Such a composite filing system, which may be referred to as optical-microfilm composite filing system, is capable of coping with all the demands (1) to (11) above, because both the advantages of the microfilm filing system and the advantages of the optical disk filing system can be enjoyed. Examples of such composite systems are required, for example, in Information Media & Technology Volume 17 No. 3, pp 97-99, Information Media & Technology Volume 18 No. 3 pp 111-114 and Reprographics Quarterly, Vol. 16, No. 4 pp 141-149, as well as in Japanese Patent Laid-Open Nos. 64855/1984, 63860/1984 and 74144/1986 et al.
Microfilm filing system also is suitable for forming data image in confidence because the user can take a photo of an original data with a camera without requiring the original to be transported outside of, for example, a room. This advantage, together with the features of the microfilm set forth as (1), (3) and (4) above, leads to an idea that the recording of images which require high degree of confidence or images which are allowed to be brought out only for a short time would be carried out successfully if the original image data is first recorded in a microfilm and then the recorded image is read by means of a microfilm scanner the output of which is digitally processed so as to be recorded in an optical disk recording apparatus.
Such a method, however, suffers from a disadvantage in that, since the optical disk file does not allow the user to visually inspect the content of the record, the operator has to conduct a manual work for inputting retrieval data, when converting the microfilm file into optical disk file. The operation for reading an image and recording the same in an optical disk requires the operator to set various reading data necessary for the purpose of reading the image, such as the readable area of frame of microfilm, resolution with which the image is converted into digital data, e.g., 8 dots/mm, 16 dots/mm and so forth, and threshold for allowing discrimination between black and white. In consequence, the speed of conversion from microfilm data into optical disk data has been impractically low. In fact, it takes about 8 hours for converting 500 pages of images. In addition, services of the optical disk recording apparatus such as retrieval and printing are not available during the manual work for converting the microfilm file into the optical disk file. In consequence, the rate of operation of the expensive optical disk recording apparatus is impractically low.